Common root rot caused by Cochliobolus sativus, is an economically important disease found worldwide. In in vitro studies, the influence of salt on the growth and pathogenicity of C. sativus was investigated using potato dextrose agar adjusted to different osmotic potentials with NaCl and KCl. Mycelial growth rates, colony diameter and germination decreased as salt concentrations increased, and NaCl caused greater negative effects than KCl. The high solute concentrations of NaCl and KCl (200–500 mM) reduced the synthesis of mycelial pigments and the size of conidia, while the production of spores was inhibited at 500 mM NaCl. Pathogenicity of C. sativus was also significantly reduced in salt treatments compared with the untreated control and this reduction was greater in NaCl than in KCl. The tolerance of the common root rot pathogen to high salt concentrations provides important information about the survival of the fungus in saline areas.